Fuel cell



FIG. 1 is a perspective view of top, front and right side of a fuel cell showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof; and,

FIG. 6 is a top plan view thereof. The bottom view is identical thereto.

The portions of the article in broken lines are shown for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a fuel cell, as shown and described. 